In the processing of tubular knitted fabric, finishing procedures typically include passing the tubular knitted fabric over a suitable spreader frame, to distend the fabric to a predetermined, uniform width and to convert the fabric to a flat, two-layer form. The fabric is continuously advanced over the spreader and, while in the flattened and distended condition, is steamed, permitting geometric adjustment of the fibers and stitches to stabilize the fabric in its uniformly distended condition. The fabric is then immediately discharged into a pair of calendering rolls, which, in effect, press the fabric, smoothing and further stabilizing it. After calendering, the fabric is gathered, typically by rolling or folding, and is taken away for cutting.
For many end uses, and particularly where the fabric is of a striped construction, it is important that the top and bottom layers of the two-layer fabric be in proper alignment or registration. Otherwise, distortions will appear in the fabric, which may be carried over into the garments which are ultimately made therefrom. Various techniques have been proposed and practiced for effecting relative adjustment of the top and bottom layers. One early and widely used technique is reflected in the S. Cohn et al. U.S. Pat. No. 2,222,794, and this involves the use of adjustable diverter bars, which enable one layer of the fabric to be diverted and/or retarded relative to the other, to bring the two layers of fabric into better alignment. Proposals have also been made for independently driving portions of the upper and lower fabric layers by variable speed rollers, in an effort to provide a greater range of adjustability. Prior proposals for such arrangements have had serious shortcomings, however, in that the independently driven rollers engage the fabric in cooperation with other rolls mounted on the spreader frame and positioned internally of the fabric. Because of the inherent bulkiness of such internal rolls, and the provisions for the support thereof, there are substantial margins of the fabric, adjacent the edge extremity, which cannot be effectively engaged by the independently driven rolls. As a result, these substantial margins may be difficult to adjust, and the finished fabric may contain significant irregularities along these margins.
In accordance with the invention, improved arrangements are provided which enable the upper and lower surfaces of the distended fabric to be controllably driven, substantially across the full distended width of the fabric, reducing to a practical minimum side edge margins which are not subject to control. Pursuant to this aspect of the invention, the spreader is provided, in its upstream portion, with a thin, flat contact plate, which may be virtually as thin as the upstream portion of the spreader frame. The contact plate is positioned in cooperating relation to upper and lower contact rolls, which extend across the full width of the machine. When the spreader frame is in position, and fabric is passing over it, the respective upper and lower layers of the fabric are grippingly engaged between the contact plate and the respective contact rolls. The presence of the contact plate does not distort the fabric, and control engagement of the fabric, out to its edge extremity, is made possible.
In accordance with another aspect of the invention, an improved calendering arrangement is provided, having the features and characteristics mentioned above, which readily accommodates lateral adjustment of the spreader frame. To this end, the spreader frame incorporates a substantially full width contact plate, which is adjustably mounted at its opposite sides in the spreader frame to accommodate a limited range of adjustment. A limited number of contact plates may be provided, to encompass the full range of width adjustment of the equipment, while at the same time providing in all cases substantially full width control over the fabric in the adjustment stage.
In accordance with another feature of the invention, an improved guard arrangement is provided, for cooperation with the upstream end of the spreader, in the region of the contact rolls. The guard arrangement is linked with the contact rolls in an advantageous manner, such that when the contact rolls are opened sufficiently to enable a new fabric section to be threaded into the equipment, the front guard automatically opens wide to provide manual access. When the contact rolls subsequently are moved into operating positions, the guard means automatically move into position to preclude access to the nip area of the contact rolls.
For a more complete understanding of the above and other features and advantages of the invention, reference should be made to the following detailed description of a preferred embodiment and to the accompanying drawings.